A coupling device for coupling a drive shaft of a flap drive with a pivot axis of a flap diaphragm of an exhaust gas flap with a C-shaped coupling element made of a wire material or the like is known from DE 10 2009 013 815 A1. In its coupling areas provided by respective C-legs, the coupling element meshes with associated recesses of the drive shaft, on the one hand, and of the pivot shaft, on the other hand, and this establishes a rotary coupling between these two components. The two C-legs are prestressed in the direction away from one another in the coupled state and thus load the pivot shaft of the flap diaphragm in the direction away from the drive shaft or the flap drive.
U.S. Pat. No. 6,598,619 B2 discloses an exhaust gas flap with a drive element configured in the form of a drive shaft and with a pivot shaft arranged coaxially thereto. A coupling device coupling the drive shaft with the pivot shaft for joint rotary motion comprises a coupling element having a box-shaped configuration.